JPH0512571Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a forced air combustion device that lowers the temperature of a burner body to a predetermined temperature during combustion.

[Conventional technology] Traditionally, water heaters, bath kettles, and other water heaters have
A heat exchanger is used in which both ends of plate fins are welded and contacted to the inner wall of a combustion case whose interior is a combustion chamber, and for water heaters, a heat exchanger is usually fixed below the heat exchanger with a fixing metal fitting. A gas burner is provided. Conventionally, in this water heater, there was little risk that the fixing fittings would be exposed to flames, and therefore there was little need to take heat resistance and durability into consideration.

[Problems to be solved by the invention] However, in recent years, in order to make equipment more compact, there has been a demand for water heaters that perform high-load combustion by using a blower to forcefully blow combustion air and fuel gas to a gas burner. There is. In this case, the fixing fitting usually has a part exposed inside the combustion chamber, and the exposed part is exposed to the flame as the flame expands due to high-load combustion and reaches a high temperature of about 1500°C.
Even when heat-resistant metals such as stainless steel are used, sufficient durability is not achieved.

Therefore, in Utility Application No. 60-164961, the present applicant proposed that the fixing metal fittings for fixing the gas burner be brought into direct contact with the wall surface of the combustion case so that the heat is quickly transferred to the plate fins of the heat exchanger through the combustion case. We proposed a water heater that uses a forced-air gas burner to maintain the fixture at a low temperature. This water heater is connected to a burner body equipped with an inlet for introducing a mixture of combustion air and fuel gas upstream of the combustion case, but when the burner body is overheated during combustion, it expands thermally. There was a problem that the air-fuel mixture could not be introduced smoothly.

Furthermore, a forced air fan whose casing is connected to the burner body may malfunction because the area around the motor becomes overheated. For this reason, when the suction of combustion air stops due to a malfunction of the blower, and the oxygen concentration drops, there is a possibility that carbon monoxide and raw gas may be released due to incomplete combustion or flame extinguishment in the gas burner. It was hot.

This invention prevents the temperature of the burner body from rising during combustion, allows a smooth introduction of the mixture of combustion air and fuel gas, and prevents the release of carbon monoxide and raw gas due to blower malfunction. The purpose is to provide a blower type combustion device.

[Means for Solving the Problems] The present invention comprises a combustion plate type gas burner that burns a mixture of combustion air and fuel gas, a combustion case inside which the gas burner is attached via a fixing fitting, and an outside. The gas burner is placed on an end surface of the peripheral portion, and the combustion case is connected to the end surface,
a burner body that introduces the air-fuel mixture into the gas burner; a blower that is connected to the burner body and forcibly blows air to the gas burner; and a blower that is interposed between the gas burner, the combustion case, the fixture, and the burner body. Adopted technical means with insulation material with low thermal conductivity.

Further, the burner body has a first heat insulator connected to the combustion case via a first heat insulating material on an outer peripheral edge thereof.
, a second protrusion connected to the gas burner via a second heat insulating material, and a second protrusion connected to the fixing fitting via a second heat insulating material.
It has a concave groove that connects through a heat insulating material.

Further, the blower includes a casing directly connected to the burner body, a fan housed in the casing, and a motor that drives the fan, and the casing includes a nozzle of a gas supply pipe that includes an electromagnetic safety valve inside. is inserted.

[Function] In the present invention, a heat insulating material is interposed between the gas burner, the combustion case, the fixing fittings, and the burner body, and the gas burner, the combustion case, the fixing fittings, and the burner body are not in direct contact. Therefore, during combustion of the gas burner, heat conduction between the gas burner, the combustion case, and the fixing fittings and the burner body is reduced, which prevents the temperature of the burner body from increasing during combustion.

Therefore, the thermal expansion of the burner body is suppressed, so that the mixture of combustion air and fuel gas can be introduced smoothly. Furthermore, the temperature around the blower connected to the burner body is lowered to a temperature at which it can safely operate, thereby preventing the blower from malfunctioning.

[Example] A first example of the forced air combustion device of the present invention is shown below.
This will be explained based on the drawings to FIG.

FIG. 1 is a diagram showing a forced-air gas water heater applied as a forced-air combustion device, and FIG. 2 is a diagram showing the main parts of this forced-air gas water heater.

(Configuration of Example) This forced-air gas water heater 1 includes a combustion case 4 including a combustion section 2 and a heat exchanger 3, and a centrifugal type gas water heater connected to the lower part of the combustion case 4 via a burner body 5. It includes a blower 7, a gas supply path 8 that supplies fuel gas to the centrifugal blower 7, and an electronic control device 9 that controls gas appliances to be described later.

The combustion section 2 includes a combustion chamber 22 that is attached to the combustion case 4 via a fixing fitting 6 and equipped with a combustion plate type gas burner 21 made of ceramic and having a large number of injection holes penetrating the ceramic plate from the front and back. The gas burner 21 is attached to the upper part of this combustion chamber 22.
and an exhaust pan 24 in which an exhaust port 23 is formed to exhaust the combustion gas burned in the exhaust gas.

The heat exchanger 3 consists of a plate fin group 31 that increases the heat exchange rate, a water supply pipe 32, and a hot water pipe 33, and is arranged between the burner 21 and the exhaust port 23, and hot water is sent from upstream of the water supply pipe 32. Water in the combustion chamber 22
The hot water pipe 33 exchanges heat with the exhaust gas inside to produce hot water.
More leakage.

As shown in FIG. 3, the combustion case 4 has a rectangular cylindrical shape, with an upper end 41 and a lower end 42 open. Flange portions 41a and 42a are provided on the outer periphery of the upper end 41 and the lower end 42, respectively.

A screw hole 43 is formed in the flange portion 41a of the upper end 41. A screw hole 44 is formed in the flange portion 42a of the lower end 42, and a screw hole (hidden by the screw 45a in FIG. 3) is formed in the rear wall 42c of the hanging portion 42b of the flange portion 42a. .

The recess 45 provided with this screw hole is recessed from the rest of the rear wall 42c, and only the inner wall surface of this recess 45 contacts the burner body 5.

Further, a flange portion 25 a is provided around the lower end 25 of the exhaust pan 24 in correspondence with the flange portion 41 a of the upper end 41 of the combustion case 4 .

Flange portion 41a of combustion case 4 and exhaust pan 2
The flange portion 25a of No. 4 is divided into two parts in an L-shape, and has screw holes 27a and 28a formed therein.
They are placed on top of each other with heat insulating plates 27 and 28 which also serve as gaskets interposed therebetween, and are fastened together with screws.

The rear wall 46 of the combustion case 4 has a main body case 47.
A metal fitting 49 with a screw hole 48 is provided for attaching the combustion case 4 to the rear wall 47a.

As shown in FIG. 4, the burner body 5 has a rectangular shape and is integrally molded with aluminum die-casting.
An air-fuel mixture inlet 51 is formed in the center of the bottom 50, and the top is open. The burner body 5 has a concave groove 56 surrounded by a first convex portion 54 and a second convex portion 55 formed in the outer peripheral edge portion 53 via a step 52 that holds the current plate 29 from the bottom 50 . First convex portion 54
Screw holes 58 and 59 are formed in the upper end 57 and the semicircular recess 56a of the groove 56.

Further, a screw hole 60 is also formed in the side wall of the outer peripheral edge portion 53. The upper end 57 of the first convex portion 54 and the flange portion 42a of the lower end 42 of the combustion case 4 are L
It is divided into two parts having screw holes 11a and 12a, and is overlapped with first heat insulating plates 11 and 12, which also serve as gaskets, and fastened with screws.

Furthermore, the hanging portion 42b of the combustion case 4 and the burner body 5 are arranged at a predetermined distance.
Also, the second convex portion 55, the gas burner 21, the outer peripheral edge 21a and the outer peripheral side surface 2 of the gas burner 21,
The lower end 6 of the ceramic refractory frame 61 fitted with 1b
1a refers to the second heat insulating board 1 divided into two parts in an L-shape.
3 and 14 are superimposed on each other.

The fixing fitting 6 is disposed in direct contact with the inner circumferential wall surface of the combustion case 4. As shown in FIG. Flange portion 62 at upper end 62
a and the side wall 63. The lower end 64 of the fixture 6 forms a flange portion 64a, and a screw hole 65 is formed in a semicircular protrusion 65a of the flange portion 64a.

The flange portion 64a is connected to the groove 5 of the burner body 5.
A third heat insulating material 15, 16 is fitted into the recessed groove 56 so as not to contact the wall surfaces on both sides thereof, is divided into two parts in an L shape, forms screw holes 15a, 16a, and also serves as a gasket. are placed one on top of the other and fastened with screws.

The semicircular protrusion 65a fits into the recess 56a of the groove 56 of the burner body 5, and there is a predetermined gap between the inner and outer peripheral surfaces of the fixture 6 and the burner body 5 so that they do not come into contact with each other. It is used for positioning.

Here, the refractory frame 61 may be formed integrally with the gas burner 21, but in order to improve thermal shock resistance, it is desirable to form it separately as in this embodiment.

First to third insulation boards 11 to 16 and insulation board 2
Two sheets of each of 7 and 28 are stacked on top of each other, and aluminum foil is placed as a reinforcing material between the heat insulating plates to provide strength.

In addition, the first to third heat insulating boards 11 to 16 and the insulating boards 27 and 28 are preferably made of materials that have excellent fire resistance and relatively low thermal conductivity. 0.056kcal/m・h・deg) or glass fiber (thermal conductivity: 0.036kcal/
m・h・deg) is used.

The centrifugal blower 7 includes a cylindrical Sirotsko fan 71, a scroll casing 73 that accommodates the fan 71 and has an open suction port 72, and a motor (not shown) that drives the fan 71.

The gas supply path 8 is integrally molded with the scroll casing 73 and includes a gas jet nozzle 81 that discharges fuel gas, a gas supply pipe 82 that supplies fuel gas to the gas jet nozzle 81, and a gas control unit 83. Become.

The gas control unit 83 includes a gas ejection nozzle 81
an electromagnetic safety valve 84 that is provided between the gas supply pipe 82 and the gas supply pipe 82 and that opens and closes when energized or de-energized; a governor valve (not shown) that is provided downstream of the safety valve 84 and adjusts the gas flow rate; An electromagnetic proportional control valve 85 is provided on the downstream side of the governor valve and has an opening ratio that is variable depending on the amount of energization.

An orifice 86 for adjusting the supply pressure and flow rate of fuel gas is attached to the other end of the gas jet nozzle 81.

The electronic control device 9 includes a start switch (not shown) that is turned on when the gas water heater 1 is used, and a temperature control volume (not shown) that is operated by the user to set the temperature of water flowing out from the hot water pipe 33. 1), a spark electrode 92 that blows sparks on the combustion surface of the gas burner 21 at the time of ignition in response to input from a thermocouple 91, etc. that detects the oxygen supply state of the flame of the gas burner 21, a motor of the centrifugal blower 7, and a gas control unit. Controls energization and de-energization of devices such as 83.

(Operation of the Example) The operation of the gas water heater 1 of this example at a room temperature of 25° C. will be explained based on FIGS. 1 to 5.

In the gas water heater 1, when the start switch is turned on, the fan 71 of the centrifugal blower 7 rotates, and combustion air is supplied to the gas burner 21 from the suction port 72 of the scroll casing 73.

Then, the electronic control device 9 outputs an output to the safety valve 84 and the proportional control valve 85 of the gas control unit 83 to open the safety valve 84 and the proportional control valve 85. Therefore, fuel gas is drawn into the scroll casing 73 and mixed with fuel air. Then, when the air-fuel mixture passes through the inlet 51 of the burner body 5 and the spark electrode 92 generates a spark discharge, it is quickly ignited and burned in the gas burner 21.

At this time, the exposed portion of the fixing fitting 6 (the flange portion 62 of the upper end 62
In a), when exposed to flame, the inner peripheral surface of the refractory frame 61 also becomes red hot. The temperature of the side wall 63 and the flange portion 64a of the lower end 64 of the fixture 6 is 400°C.

Heat is smoothly transferred to the combustion case 4 in contact with the side wall 63 of the fixture 6 (in the order of the fixture 6 → combustion case 4 → plate fin group 31 → water supply pipe 32 and hot water supply pipe 33 of the heat exchanger 3). The maximum temperature is 150℃.

These combustion case 4, fixture 6, outer peripheral edge 21a of gas burner 21 and fireproof frame 61, first convex portion 54, second convex portion 55 of burner body 5,
The grooves 56 are the first to third heat insulating plates 11, respectively.
~16.

For this reason, in the case where the burner body 5 is attached to the direct combustion case 4, the fixing fitting 6, the outer peripheral edge 21a of the gas burner 21 and the refractory frame 61 as in the past, the temperature of the burner body is 110°C. ~ In the burner body 5 of the present invention in which the third heat insulating plates 11 to 16 are interposed between them, the temperature can be lowered to a predetermined temperature (80°C to 85°C), so that the temperature of the mixture of combustion air and fuel gas can be lowered to a predetermined temperature (80°C to 85°C). This made it possible to implement the system smoothly.

The temperature of this burna body 5 (80℃~85℃) is
Fan 71 blows combustion air to gas burner 21
The temperature of the scroll casing 73 in which the motor and the gas jet nozzle 81 connected to the gas supply pipe 8 equipped with the electromagnetic safety valve 84 and the electromagnetic proportional control valve 85 are installed (70°C in the conventional scroll casing) It became possible to lower the temperature (previously) to as low as 55°C.

Therefore, the temperature becomes 55°C (the conventional fan motor and solenoid valve were 65°C), which allows the fan 71 motor, electromagnetic safety valve 84, and electromagnetic proportional control valve 85 to operate accurately. In the gas burner 21, when suction of combustion air stops due to malfunction of the electromagnetic safety valve 84 or the electromagnetic proportional control valve 85, or when the supply of fuel gas stops or becomes excessive, and the oxygen concentration or gas concentration decreases. , it is possible to accurately avoid the danger of emitting carbon monoxide or raw gas due to incomplete combustion or flame extinguishing.

(Modification) In this embodiment, a plate is used as the heat insulating material, but it may be of any other shape, and the material is not limited to that of this embodiment.

In this example, the forced air combustion device of the present invention was applied to a gas water heater using a combustion plate gas burner, but the forced air combustion device of the present invention can be applied not only to gas water heaters but also to gas combustion heating devices. May be applied.

In this embodiment, the burner body and scroll casing are separate bodies, but the burner body may be integrally molded.

[Effect of the invention] Since the temperature rise of the burner body during combustion can be suppressed, the thermal expansion of the burner body can be suppressed, so that the mixture of combustion air and fuel gas can be introduced smoothly.

In addition, since the temperature rise of the burner body when fueling can be suppressed, the temperature around the blower will be at a temperature that allows the blower to operate safely, reducing the release of carbon monoxide and raw gas from the gas burner due to blower malfunction. It can be avoided.

[Brief explanation of drawings]

1 to 5 show an embodiment of the forced air combustion apparatus of the present invention. Figure 1 is a sectional view showing a forced air gas water heater, Figure 2 is a sectional view showing the main parts of the forced air gas water heater, Figure 3 is a perspective view showing the combustion case, and Figure 3 is a sectional view showing the main parts of the forced air gas water heater. FIG. 4 is a perspective view showing the burner body and the first to third heat insulators, and FIG. 5 is a perspective view showing the fixture and the third heat insulator. In the figure, 1... forced air gas water heater (forced air combustion device), 4... combustion case, 5... burner body, 6... fixing fittings, 7... centrifugal blower,
8... Gas supply path, 11, 12... First heat insulating board, 13, 14... Second heat insulating board, 15, 16...
...Third insulation board, 21... Combustion plate type gas burner,
54...First convex portion, 55...Second convex portion, 56
...Concave groove, 71...Shirotsukko fan, 73...
Scroll casing, 84...Solenoid safety valve.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. (a) A combustion plate type gas burner that combusts a mixture of combustion air and fuel gas; (b) A combustion case into which the gas burner is attached via a fixing fitting; (c) a burner body on which the gas burner is placed on an end face of the outer peripheral edge, to which the combustion case is connected, and which introduces the air-fuel mixture to the gas burner; (d) a burner body which is connected to this burner body and which is connected to the gas burner; (e) a heat insulating material with low thermal conductivity interposed between the gas burner, the combustion case, the fixing fittings, and the burner body. 2. The burner body has a first convex portion connected to the combustion case via a first heat insulating material, a second convex portion connected to the gas burner via a second heat insulating material, on an outer peripheral edge thereof, and The forced air combustion device according to claim 1, which is a registered utility model, and has a concave groove connected to the fixing fitting via a second heat insulating material. 3. The blower includes a casing directly connected to the burner body, a fan housed in the casing, and a motor that drives the fan, and the casing has a gas supply pipe nozzle that includes an electromagnetic safety valve inside. The forced air combustion device according to Claim 1 of the Utility Model Registration Claim, characterized in that the device is inserted.